1. Field of the Invention
This invention relates to a pivotal door structure, and more particularly is directed toward a door structure adapted to open pivotally from either side.
2. Description of the Prior Art
Generally, a door structure pivotally opens from one side and is supported on hinges or the like on the other side. In many situations, it is desirable to be able to open a door, such as the door of a refrigerator or a cabinet, from either its left side or its right side in order to be able to avoid furniture and the like. In other situations, such as doors within a hallway, it may be desirable to open the door from either side and in either direction. Further, it is highly desirable to be able to open emergency exit doors by pushing on either side and without using handles.
A car door is described in U.S. Pat. No. 613,495 wherein a generally upright lever is pivoted about its fulcrum and moves a pair of rods in a generally horizontal direction to pivot four upright bolts about their fulcrums and thereby move four horizontally disposed bolts inwardly or outwardly of metallic keepers, arranged in suitable relation thereto on the door-jams, for respectively opening or locking a freight-car door.
U.S. Pat. No. 1,212,820 describes, particularly in its FIGS. 3-5, a locking cam comprising a circular plate which is turned by an actuating handle and carries a pair of pivotal connections at its edge which engage the ends of two horizontally disposed arms and also carries a third pivotal connection which engages cams along the inner edges of the arms, whereby revolving the actuating handle causes the plate to rotate and the two arms to be cammed inwardly or outwardly for opening or locking a door of a grain car.
A door mounting mechanism is described in U.S. Pat. No. 1,550,205 which comprises an operating handle for rotating an operating link on a pivot, thereby sliding a pair of bar members inwardly or outwardly, whereby a pivotal connection with sockets is released or formed, respectively, on either side of a door so that the door can be swung from either side and cannot be detached from both sides simultaneously.
U.S. Pat. No. 2,261,147 describes a disconnectible hinge structure which supports a refrigerator door so that it may be opened from either side. This structure comprises a pair of cooperating hinge elements which may be moved into operating position on a hinge axis and which have thrust and radial bearing means for supporting the load of the door. One of the hinge elements is secured to the edges of the door; the other is connected to the door frame. They are also relatively movable so that a recess formed in one of them will receive a projection formed in the other, thereby producing a pin and socket interengagement on which the door may be cooperatively swung from closed to open position with releaseable latch means.
U.S. Pat. No. 2,783,115 describes a cabinet having a door which is connected by means of a pair of hinges at its first side to the corresponding side of an upper panel which is in turn connected at its second side to the corresponding side of the cabinet. The door is further connected along its second side by means of a pair of hinges to a corresponding side of a lower panel which is in turn connected by means of a pair of hinges on its first side to the corresponding side of the cabinet. When the door is opened along its second side, it brings with it the upper panel. When the door is opened along its first side, it brings with it the lower panel. The contents of the upper part or of the lower part of the compartment may thereby be selectively observed.
A double action pivoting door is described in U.S. Pat. No. 3,048,899. The door comprises a push-pull handle, having a V-groove in the midway position of its shaft, which is disposed along each edge. Upper and lower vertical shafts are aligned with the V-groove of each handle, and each vertical shaft has a ball at its end which engages the V-groove on opposite sides thereof. Upper and lower horizontal beams are also disposed in the door and have recesses in the end thereof which engage corresponding recesses in the respective upper and lower vertical shafts. The upper and lower horizontal beams further comprise a spherical indentation in their respective upper and lower edges near each end and a quadrantal recess between the end and the respective upper and lower edge into which a ball of a spring-loaded pivot assembly is received. Pushing or pulling on the handle on the opposite edge of the door similarly actuates its upper and lower vertical shafts, moves the upper and lower horizontal beams sidewardly in the other direction, and similarly secures the spring loaded pivot assembly on the opposite edge, whereby the door can be selectively opened from either side and in either direction.
A reversibly mounted cabinet door is described in U.S. Pat. No. 3,863,391 which has hinge pins at its upper and lower ends on each side thereof, the hinge pins being spring biased to extend beyond the peripheral edges of the door for disposition in hinge plates mounted on the cabinet adjacent to the upper and lower ends of each side of the door. A handle includes cam actuators which cooperate with the upper and lower hinge pins on the side on which the handle is mounted to retract these hinge pins from support in the hinge plates so that the door is hinged to the cabinet on the opposite side of the door from the handle.
U.S. Pat. No. 3,889,419 describes a door for a refrigerator which is capable of being opened in either a right-handed or a left-handed direction. The refrigerator cabinet has a hinge pin disposed in each corner of the opening, and the door is provided with two bolt assemblies having a bolt member which is slidable into entrapping engagement with the hinge pin in order to form a hinge mounting adjacent to either the left or the right hand side of the door. The door is also equipped with a pair of handles disposed on the right and left hand sides of the door for engaging the bolt assemblies in order to shift the bolts to form the hinge assembly on the side opposite to the handle that is actuated.
U.S. Pat. No. 4,222,149 discloses a door hinge arrangement that permits opening of the door alternatively at either side. This arrangement comprises mountings for attachment to the door at its upper and lower edges, each mounting carrying two hinge sets for engagement with hinge pivots fixed to the frame of the door. A longitudinally slidable trapping member is associated with each mounting. Each trapping member has a guide constructed so that when the door initially opens on one side, each trapping member is so displaced as to trap the corresponding hinge pivot in the hinge seat at the other side of the door, the hinge seats being located at the outer ends of the mountings and the trapping members having a length not exceeding the distance between the outer ends of the hinge seats. A guide is also arranged for displacing the trapping members in a direction away from the side at which the door is being opened.
A two-sided cabinet door, in which either side is pivotally openable and both sides are self-closing, is described in U.S. Pat. No. 4,230,381. The two-piece openable cover comprises a retaining lid and a captured lid which are intended to be joined together and mounted on top of the cabinet box having an upward facing opening needing to be covered. The retaining and the captured lids are interconnectable in either a pivotal or a sliding configuration; either lid may be separately opened, and both are self closing when pivotally connected. Either lid is also slideably openable when the lids are slideably connected.
U.S. Pat. No. 4,503,582 relates to a hinged structure for mounting a door to a cabinet for selective opening of the door from either side of the cabinet. This hinge structure includes a slide bar which is selectively positionable as a result of the opening of the door from either side of the cabinet to a thrown position. The structure also includes locking elements for retaining the slide bar in the thrown position as long as the door remains pivoted in the open position, thereby preventing the pivoting hinge structure from being removed from the cabinet.
In all of these devices of the prior art, the mechanisms are complicated and involve numerous parts. There is accordingly a need for a double-acting door structure which is simple in construction and operation and which comprises few parts.
It is to be understood that a door, as discussed hereinafter, has two surfaces and four edges, i.e., a front surface, a rear surface, a first side edge, a second side edge, a top edge, and a bottom edge. Each surface has two sides, extending from the middle to its first or to its second side edge. The front surface, for example, has a right side and a left side, and the right side is back-to-back with the left side of the rear surface. The door structure is defined as a double-acting door and a door frame which comprises a lintel in proximate relation to the top edge of the closed door and a sill in proximate relation to the bottom edge of the closed door.